From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Zhang Rui <rui.zhang@intel.com>,
Eduardo Valentin <edubezval@gmail.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux PM list <linux-pm@vger.kernel.org>,
"Li, Philip" <philip.li@intel.com>
Subject: Re: [GIT PULL] Thermal management updates for v4.17-rc1
Date: Fri, 13 Apr 2018 13:10:21 +0200 [thread overview]
Message-ID: <417cb724-2fcf-717f-63bf-9a479cc0d540@linaro.org> (raw)
In-Reply-To: <10298074.ogKH1ypqfx@amdc3058>
On 13/04/2018 12:41, Bartlomiej Zolnierkiewicz wrote:
> On Friday, April 13, 2018 12:30:04 PM Daniel Lezcano wrote:
>> On 13/04/2018 11:28, Bartlomiej Zolnierkiewicz wrote:
>>
>> [ ... ]
>>
>>>>> It is okay to return 0 because this code-path (the default one) will be
>>>>> never hit by the driver (probe makes sure of it) - the default case is
>>>>> here is just to silence compilation errors..
>>>>
>>>> The init function is making sure cal_type is one or another. Can you fix
>>>> it correctly by replacing the 'switch' by a 'if' instead of adding dead
>>>> branches to please gcc?
>>>>
>>>> if (data->cal_type == TYPE_TWO_POINT_TRIMMING) {
>>>> return ...;
>>>> }
>>>>
>>>> return ...;
>>>
>>> I'm not the one that added this switch statement (it has been there since
>>> 2011) and I would be happy to remove it.
>>
>> Actually the switch statement was fine until the cleanup.
>
> I don't see how it was fine before as the driver has never used the default
> case (always used TYPE_ONE_POINT_TRIMMING or TYPE_TWO_POINT_TRIMMING).
>
> Could you please explain this more?
>From commit 480b5bfc16e17ef51ca1c
+++ b/drivers/thermal/samsung/exynos_tmu.c
@@ -260,7 +260,7 @@ static int temp_to_code(struct exynos_tmu_data
*data, u8 temp)
temp_code = temp + data->temp_error1 -
pdata->first_point_trim;
break;
default:
- temp_code = temp + pdata->default_temp_offset;
+ WARN_ON(1);
break;
}
@@ -287,7 +287,7 @@ static int code_to_temp(struct exynos_tmu_data
*data, u16 temp_code)
temp = temp_code - data->temp_error1 +
pdata->first_point_trim;
break;
default:
- temp = temp_code - pdata->default_temp_offset;
+ WARN_ON(1);
break;
}
I'm not saying the code path was fine but from the compiler point of
view, it was. By removing the defaulting temp value there is a code path
gcc sees the temp variable as not initialized.
Your cleanups are relevant.
> --
> Bartlomiej Zolnierkiewicz
> Samsung R&D Institute Poland
> Samsung Electronics
>
--
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next prev parent reply other threads:[~2018-04-13 11:10 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-11 8:41 [GIT PULL] Thermal management updates for v4.17-rc1 Zhang Rui
2018-04-12 0:01 ` Linus Torvalds
2018-04-12 5:08 ` Zhang Rui
2018-04-12 16:55 ` Linus Torvalds
2018-04-12 17:42 ` Daniel Lezcano
2018-04-13 4:08 ` Eduardo Valentin
2018-04-13 5:29 ` Zhang Rui
2018-04-13 5:39 ` Zhang Rui
2018-04-13 8:55 ` Bartlomiej Zolnierkiewicz
2018-04-13 9:00 ` Daniel Lezcano
[not found] ` <CGME20180413090820epcas1p17dd97e3815909e0714f9d5a80eb82be9@epcas1p1.samsung.com>
2018-04-13 9:08 ` Bartlomiej Zolnierkiewicz
2018-04-13 9:19 ` Daniel Lezcano
[not found] ` <CGME20180413092901epcas2p43245301152a01c782620f0ab95b2a692@epcas2p4.samsung.com>
2018-04-13 9:28 ` Bartlomiej Zolnierkiewicz
2018-04-13 10:30 ` Daniel Lezcano
[not found] ` <CGME20180413104120epcas1p319b9e78b025cb68f810f047c67a48362@epcas1p3.samsung.com>
2018-04-13 10:41 ` Bartlomiej Zolnierkiewicz
2018-04-13 11:00 ` [PATCH] thermal/drivers/exynos_tmu: Fix warnings in temp_to_code / code_to_temp Daniel Lezcano
2018-04-13 11:08 ` Bartlomiej Zolnierkiewicz
2018-04-13 11:10 ` Daniel Lezcano [this message]
[not found] ` <CGME20180413111242epcas1p4cd5ecac004dd9c1e00e1608088ff88e2@epcas1p4.samsung.com>
2018-04-13 11:12 ` [GIT PULL] Thermal management updates for v4.17-rc1 Bartlomiej Zolnierkiewicz
[not found] ` <CGME20180413112148epcas1p3f657cb50af4151d41f8c404e6b0d5fab@epcas1p3.samsung.com>
2018-04-13 11:21 ` Bartlomiej Zolnierkiewicz
2018-04-13 10:08 ` Eduardo Valentin
2018-04-13 10:25 ` Eduardo Valentin
2018-04-13 10:27 ` Bartlomiej Zolnierkiewicz
2018-04-15 8:51 ` Eduardo Valentin
2018-04-13 8:50 ` Bartlomiej Zolnierkiewicz
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